Producing metallic layers on printed sheets using a foil transfer method is known. For example, EP 0 569 520 B1 describes a printing material and a printing apparatus that uses such a foil material. This reference relates to a sheet processing machine that has a feeder and a delivery unit. Printing units and a coating module are located between the feeder and delivery unit. An adhesive pattern is applied using a flat printing process in at least one of the printing units. This adhesive pattern is applied using a cold printing process and has a specific, imaging design. The coating module includes a foil guide that is located downstream of the printing unit and includes an impression cylinder and press cylinder. The foil guide is designed such that a foil strip or transfer foil can be guided from a foil supply roll through a transfer gap in the coating module between the impression cylinder and the press cylinder. The foil strip is rewound on the outlet side after leaving the coating module. The transfer foil includes a support layer to which image-forming layers, such as metallic layers (for example, made of aluminum) can be applied. A separating layer is provided between the metallic layer and the support foil. The separating layer ensures that the metallic layer can be removed from the support layer.
Each printing sheet is provided with an adhesive pattern as they are transported through the printing unit. The printing sheet is then guided through the coating module and the printing sheet resting upon the impression cylinder is brought into contact with the foil material via the press cylinder. In this case, the metallic layer positioned on the bottom of the transfer foil bonds tightly with the areas of the printing sheet supplied with the adhesive. As the printing sheet continues to move forward, the metallic layer adheres only in the area of the adhesive pattern. The metallic layer is then removed from the support film in the area of the adhesive pattern. The consumed transfer foil is then rewound. The printed sheet is delivered in the coated state.
Utilizing coating modules of this kind, for example, in printing units of printing machines is known. However, a disadvantage of these modules is that they cannot be utilized in a flexible manner.